Cylinder dye test



March 13, 1956. s, DART ET AL CYLINDER DYE TEST 2 Sheets-Sheet 1 Filed Sept. 13, 1950 MM M WAT w Ju/HM A MD f 0 HL Y E WM Y ww a March 13, 1956 s. L. DART ETAL CYLINDER DYE TEST 2 Sheets-Sheet 2 Filed Sept. 13, 1950 .in l

JNVENTORS. JOHN P. HOLL/HAN.,JR. SIDNEY L. DART ATTDANEY- United States PatentO CYLINDER DYE TEST Sidney L. Dart, Chester, and John P. Hollihan, Jr., Garden City, Pa., assignors to American Viscose Corporation, Wilmington, Del., a corporation of Delaware This invention relates to ,a method and apparatus for collecting andpreparing samples-of yarns for liquid treatments, particularly a .dyeing operation, and determining quantitatively the eifect of the liquid'treatment, for example, the extent of dye absorption in progressive sections of .a sample. This invention is particularly useful in providingdyed yarn samples of ample area for observation or testing which havebeen subjected to substantially the same conditions as if the strand was formed into a dyed fabric.

In;the control of yarn manufacturing operations as well as in experimental Work, it is highly advantageous to evaluate within a few hours the dyeingcharacteristics that a strand will exhibit in thewoven material without subjecting the strands to the various dyeing and fabricating steps entailed in the production of a fabric. Although the prior art disclosed mechanical means for collecting yarn samples for testing purposes, no satisfactory equipment is described for preparing dyed yarn samples which are substantially equivalent to a dyed fabric comprising the yarn from the standpoint of evaluating the dyeing characteristics of the yarn.

It is an object of the present invention to provide a method'and an apparatus for preparing dyed-yarn samples whereinthe yarn is formed into'a panel of adequate width for observation and the strand is laid in many parallel courses depositediclosely together to form a substantially solid layer of one strand in thickness, the passes being deposited under uniform stretching. Itis another object :to provide the samples in a form in which -they may be removed from the forming apparatus for storage. It is alsoanobject to prepare dyed yarn samples within a few hours which are equivalent for dye-testing purposes to a fabric comprising the yarn. It is especially :anobjectto provide apparatus in which the dye-testyarn samples are subjected to a treatment which is equivalent to the slashing treatment given to warp yarns of the fabric.

Other objects, features and advantages will become apparent .in the following description of the invention and the illustrated in Fig. 1 illustrating the sample-rewinding operation;

'Fig. 3 is a plan view of a portion of :the apparatus shown in Figs. 1 and 2 illustrating a sample-scanning operation;

Fig. 4 is a broken longitudinal section of a cylinder on which a yarn'sample is collected and supported;

.Fig. 5 is an elevation view of centrifugal liquid-extracting apparatus with a sample-supporting cylinder-in place; and

Fig. .6 is a pictorial view of apparatus for carrying out .a dyeing operation.

In accordance with the invention, a yarn sample in a single compact layer of :windings is wound ontoithe :upper 2,737,806 Patented Mar. 13, 1956 roll of a pair of rolls spaced one above the otherhaving parallel horizontal axes of rotation and .detachably ,supported within a machine vfor supporting and rotating the rolls. The sample is stretched while being rewound onto the lower roll at a higher peripheral speed than the upper roll, the lower roll being partly submerged within a bath so that the rewound sample is wetted as well as stretched. The roll on which the sample is wound is transferred to apparatus adapted to support and rotate the roll within a bath comprising, at first, a cleaning or scouring solution and thereafter, a dye solution. After a required lapse of time, the dye solution is diluted with continuous additions of fresh water and allowed to overflow until the original dye solution is substantially replaced with clear water in order to wash the dyed wound yarn. The roll is then rotated at a high speed to remove liquid centrifugally from the sample. After air drying, the roll and the sample are placed in the original winding machine and the sample is scanned along a path extending in a direction longitudinally of the roll during rotation of the roll by a reciprocably mounted device comprising a light source and an instrument for measuring the intensity of light reflected from the sample.

Fig. 1 illustrates an apparatus 5 for supporting and rotating a pair of cylinders or rolls such as the roll 6 which is supported between a driven spindle 7 and a stationary or freely rotatable spindle 8. A roll 10 shown in Figs. 2 and 3 is supported by a driven spindle 1'1 and a spindle 12 similar to spindle 8. As shown in Fig. l, a strand is being collected on the cylinder "6, the strand being unwound from a bobbin '14 and passed through a tension device 15 for placing the yarn underuniform tension as it passes through a traverse guide 16 to the roll 6. The guide 16 is mounted on a post 18 which also supports a light-sensitive device 19. The post 18 is fixed to a carriage 2t) slidably supported on a track-line frame 21. The carriage 20 is moved longitudinally of the frame 21 by a rotatable screw 23 with which it is in threaded relationship. The rotation of the screw 23 is synchronized with the rotation of the spindle 7 by suitable gearing within the housing 22 to wind a yarn sample onto the cylinder 6 so that the windings are laid substantially in side by-side contact and the surface of "the cylinder is not appreciably visiblethrough the windings. The end-portion of the'yarn first laid on the cylinder is secured by cleat 24 and a screw 24a; at the other end of the cylinder, the other-endportion of the yarn sample may be secured by another cleat 25 and a screw 25a or secured directly to cylinder 10 by a similar cleat preparatory to rewinding the sample onto the lattercylinder.

A trough 27 is supported between upright stationary frame members 28 and 29 0f the apparatus 5 just below the spindles 11 and 12 so that when the trough is filled to a desired level at27a, a portionof the cylinder 16 is submerged within the liquid. The trough is connected with a liquid supply line 26 and provided with an overflow duct 30 so that the liquid may be maintained at a constant level. For standardization, rolls 6 and it may be of the same dimensions so that they are interchangeable with a large number of other rolls that may be needed in addition to those supported in the apparatus to carry out extensive or routine testing procedures. However, when the rolls are of uniform size, suitable gearing or other drive means .is provided Within the apparatus 5 to drive the rolls .6 and 10 at different peripheralspeeds. The yarn is stretched when being transferred from roll 6 to roll 10. On account of the :presentpractice known .to the trade as warp slashing which necessarily involves some stretching when applied to rayon yarns, the apparatus is adjusted for a difference in the speeds of rotation of spindles "7 andlliof approximately 6 .percent. The :drive for "these spindles may be readily modified, such as by the exchanging of gear sets, to develop different speed ratios. If preferred, however, a loading roll corresponding to roll 6 may be provided having a smaller diameter than the roll 10, and the apparatus constructed with driving spindles to operate it at the same speed of rotation.

Fig. 2 illustrates the apparatus at a stage in its operation wherein a sample has been partly rewound onto the cylinder 10. When the rewinding is completed, the end of the yarn sample is secured to the cylinder 10 by cleat 31. The sample and the cylinder may thereafter be removed from the apparatus 5 by pulling in an axial direction on a knob 32 which pulls the spindle 12 from the recessed end of the cylinder.

The construction of the cylinders is illustrated in Fig. 4 wherein a cylinder 6a such as used in the present invention is recessed at both ends to receive either pair of spindles. To impart drive to the cylinder, the recess at one end is provided with a cross-wise slot 34 to receive pins extending radially from the driving spindle such as the pins 35 of spindle 11.

Fig. 6 illustrates apparatus into which the cylinders are transferred after yarn samples are rewound onto a cylinder as described in connection with the step illustrated in Fig. 2. The apparatus of Fig. 6 comprises a tank 36 adapted to contain a bath and to receive and discharge liquids comprising the bath through outlet and inlet lines 37 and 38. The tank 36 is preferably equipped with a heater (not shown) for automatically controlling the bath temperature. A carriage 40 is provided for supporting the cylinders which may be raised or lowered into the tank 36. A cylinder such as the one shown in ghost outline is supported between any pair of the horizontally spaced rotors 41 on coaxial collars 42 mounted on the end-portions of the rotors adjacent the tank walls. The rotors are provided with thin but not sharp helical webs 43 which have a smaller diameter than the collars 42. The webs provide mild agitation of the bath in the tank 36 and particularly in the vicinity of surfaces of the rolls supported by the rotors. The rotors 41 are spaced sutiicienty so that a cylinder may be supported between any two adjacent rotors. The rotors are driven by means such as the chain drive shown actuated by a motor 44 and the gear reduction unit 47. An idler sprocket 45 is mounted adjustably on a vertical frame portion of the carriage 40 for keeping the sprocket chain 46 substantially taut. The carriage is supported on the piston rod 48 of a fluid cylinder 49. Valve means (not shown) in the fluid supply line 50 may be used to control the cylinder when raising or lowering the carriage.

Fig. 5 illustrates a device 52 in which the rolls are rotatably supported after being removed from the dyeing apparatus of Fig. 6. The device 52 is used for rotating the rolls at high speed to centrifugally removed loosely held water or other liquid from the yarn sample wound on the roll 10 and comprises a motor 53 having a spindle 54 contiguous with its shaft, and a spindle 55 in resilient engagement within the recessed end of the roll, the motor and the spindle being mounted on the frame 56. The speed of the motor may be regulated by means such as a rheostat 57.

Fig. 3 illustrates the roll 10 in position between the spindles 11 and 12 while being progressively scanned by the portion of the apparatus of the invention used to determine the uniformity with which the yarn sample absorbed the dye contained in the bath in the tank 36. Housed in a device is a light source such as an electric bulb. A beam from the light source is passed along a path extending at an oblique angle with the axis of the roll 10 on the windings of the yarn sample covering the surface of the roll. A photelectric cell 19 is positioned with respect to the light source to receive the reflection of the light beam from the yarn surface. Variations in the intensity of the light reflected from the yarn surface are registered as current variations by the photoelectric cell which are transmitted to a current amplifier til of a conventional recording instrument 64 which produces a trace 65 indicating the variations in the intensity of the reflected light upon a chart 66 which advances at a uniform rate.

In the practice of the invention, the cylinders on which the yarn samples are wound are approximately 1% inches in diameter and 14 inches in length. About 10 inches of the length of the cylinders are available for the winding of the sample. A total of approximately yards of yarn or 15 yards to the inch may be wound onto each cylinder. For example, a succession of 10 test panels each about 1 inch in length and 15 yards long may be wound in series onto each cylinder, the various yarn sections being connected in series by knots.

The trace line 65 indicates the amount of light reflected from the sample as the photoelectric cell scans the yarn surface. Movement of the scanning equipment comprising cell 62 and a light source 60 is effected by traversing the carriage 20 on which they are mounted. The light beam passing from the lamp 60 and the beam reflected into the measuring cell 19 is normally adjusted to cover a spot on the yarn sample of about 4 yarn diameters in width. Consequently, the light reflected is the average of the reflection from four adjacent windings. However, the light beam may be focused into a smaller or greater pattern, if desired. Low values on the chart 66 indicate less light reflectance. Less light reflectance means greater absorption of light by the yarn sample; light absorption is proportional to the dye absorption by the yarn. Thus a low trace line on the chart means a dark dyeing sample and vice versa.

In conducting a test according to the invention, samples are normally taken from yarn received in the form of spools, cones or cakes. The samples may be, for example, so seleeted as to obtain yarn portions from the outer, middle, and innermost windings of the yarn package. The yarn may be fed from the package through an automatic measuring device to give the number of yards desired when feeding it onto the cylinder. The length of yarn may vary from a 15 yard panel to the full yardage carried by the cylinder. Successive samples on a single cylinder may be tied together in any desired manner, such as with a weavers knot. In being passed onto the loading roll 6, the yarn comprising the samples is passed through a tensioning device so as to feed the yarn onto the roll at uniform tension.

The yarn is then attached to the roll 10 which may be of slightly different diameter, if the driving spindle speeds for each roll are the same. When both rolls in the machine of Fig. 1 are of the same diameter, the roll 10 is rotated at a slightly faster speed to obtain an approximately 6 percent stretch in the yarn as it is wound onto the roll 10; the latter roll is partly immersed in water. The windings are laid on the roll 10 as close together as possible. For winding yarns of finer denier, the rotation rate of the screw 23 may be decreased by changing the gears within the housing 22.

One or more cylinders having samples wound thereon may be placed in the carriage 40 and submerged in the bath contained by the tank 36. The initial bath will consist of water containing a detergent and heated to a temperature near the boiling point. The cylinders which are supported by the carriage are rotated for approximately 7 minutes. The carriage is lifted and a solution at a desired concentration of a standard dye such as Brilliant Benzo Blue 63A is added and stirred into the water bath, then a saturated salt solution is added and the bath is again stirred. The carriage containing the cylinders is lowered into the dye bath for approximately 5 minutes with the temperature of the bath maintained just below the boiling point. Thereafter, unheated water is added and the bath is overflowed until clear of the dye. Rotation of the cylinders is continued until they are removed from the carriage and placed in the rotating device 52 of Fig. 5. After excess liquid is removed,

a cylinder is placed in an upright position and allowed to air dry for about one hour.

With the trough 27 being drained of water, the cylinder and the dried yarn sample wound thereabout is then placed in the original winding apparatus 5 between the spindles 11 and 12 and scanned by the light-sensitive apparatus hereinbefore described. The apparatus is preferably housed in a cabinet or room which may be completely darkened during the scanning operation. In this manner, variations in the absorption of the light beam projected from the lamp 60, occurring along the windings of the cylinder, produce variations in the reflection of the beam from the yarn sample and are progressively recorded on the chart. By setting up predetermined standards, the results as indicated on the chart may be converted to give a quality rating with respect to the dye absorption of yarn.

While preferred embodiments of the invention have been shown and described, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. Apparatus for collecting and preparing yarn samples for dye testing and for measuring the uniformity of dyeing comprising a plurality of similar portable rolls of like size on which to wind a yarn, and a device having means for supporting and rotating a pair of the rolls in spaced opposed relationship with their axes of rotation parallel, said means comprising a spindle for driving each roll, means for driving the spindles at different relative speeds, means for partly immersing the more rapidly driven roll in a liquid, a yarn guide, a movable light source, a light-intensity measuring means comprising a movable light-intensity sensing means, means for supporting the guide, the light source, and said sensing means for movement along paths extending parallel to the axes of the pair of rolls, the guide being supported throughout its path adjacent the yarn-supporting surface of the more slowly driven roll, the light source and said sensing means being supported in relative fixed relationship throughout their path laterally with respect to one of the rolls and aligned with respect to the surface thereof for reflection of light projected onto the surface into said sensing means, and means connected in drive relationship with the driving means for moving the guide, the light source, and the light sensing means lengthwise along respective paths at rates having a predetermined ratio with respect to the speed of rotation of either spindle.

2. Apparatus for collecting and preparing yarn samples for dye testing comprising a plurality of similar portable cylinders of the same size on which to collect samples of yarn in helical windings, and a device having means for supporting a pair of the cylinders in spaced opposed relationship in parallel axes of rotation, said means comprising a spindle for driving each cylinder, means for driving the spindles at different relative speeds, a trough for partly immersing the more rapidly driven roll in a liquid, a yarn guide, a movable light source, light-intensity measuring device comprising a movable light-intensity sensing means, means for supporting the guide, the light source, and said sensing means for movement along paths extending parallel to the axes on said pair of cylinders, the guide being supported throughout its path adjacent the yarn-supporting surface of the more slowly driven cylinder, the light source and said sensing means being supported throughout their path laterally with respect to a yarn-supporting surface of one of the cylinders, the light source being aligned with respect to the adjacent cylinder surface for directing a beam of light at an oblique angle with respect to the axis of the surface, the sensing means being positioned relative to the cylinder surface which receives said beam to receive the reflection thereof, and means connected in synchronism '6 with the means for driving the spindles for selectively moving the guide and simultaneously moving the light source and the sensing means along respective paths at rates proportional 'to'the speed of said driving means.

3. Apparatus for collecting and preparing individually portable yarn samples for dye testing comprising a plurality of substantially identical portable cylinders of which each cylinder is adapted to receive and store a" continuous yarn sample wound thereabout in helical windings, and a devicefor supporting and (rotating a pair of thecylinders in spaced substantially coextensive relationship along parallel axes of rotation for the purpose of collecting a sample of yarn on one cylinder and thereafter unwinding the yarn from said cylinder directly onto the other cylinder while progressively stretching and wetting all sections of the yarn; the device comprising a transmission for driving the cylinders simultaneously at a predetermined ratio of speeds; a trough positioned around a longitudinal portionof the more rapidly driven cylinder; means for maintaining a liquid in the trough at a predetermined level above a longitudinal lower portion of the adjacent cylinder; the axes being relatively disposed for passage of the yarn directly from the periphery of one cylinder to the other without interference with other portions of the device; and means for feeding yarn onto the more slowly driven cylinder comprising a traverse guide having a path of movement extending parallel to the axes of the cylinders supported by the device and in adjacent spaced relation to the surface of the more slowly driven cylinder, and means connected in synchronous relation with the transmission for driving the guide along its path at a rate relative to the rotation of the more slowly driven cylinder whereby a yarn passing through the guide is progressively wound onto the periphery thereof in closely juxtaposed windings.

4. A method of dye testing yarn comprising the steps of forming a strand into a group of helical juxtaposed windings, unwinding and wetting said strand at a predeermined rate, collecting at least a portion of the strand at a rate greater than, and in fixed ratio with, said rate of unwinding into a unit of stretched juxtaposed helical windings, transferring the unit to a liquid dye solution, revolving the unit in the solution for a predetermined period of time, separating the unit from the solution and revolving the unit rapidly to remove loosely held liquid, drying the unit, directing a beam of light against the exterior surface of the unit, moving the unit and the light beam to obtain relative rotation therebetween with respect to the axis of the helical windings of the unit and relative movement therebetween in a direction parallel to the axis to progressively expose to the beam the entire length of any selected continuous portion of the strand forming the unit, and measuring the intensity or" the light reflected from the unit.

5. in a method of forming a continuous length of yarn into a rigidly supported sample equivalent for testing purposes to a fabric comprising slashed warp yarn, the steps of winding the yarn onto one cylindrical surface at uniform tension into a single layer of juxtaposed windings, then unwinding said unit onto a second cylindrical surface of the same diameter disposed in axially parallel relation to the first named surface, turning the second cylindrical surface more rapidly than the unwinding rate of said first surface but at a rate in fixed ratio with that of the first surface to wind a single layer of uniformly stretched juxtaposed windings in substantially side-byside contact on said second surface, and wetting the yarn as it winds onto the second surface.

6. in a method of forming a continuous length of yarn into a rigidly supported sample equivalent for testing purposes to a fabric comprising slashed Warp yarn, the steps of forming the yarn into a unit of helical juxtaposed windings of uniform diameter about an axis, unwinding and wetting the yarn of said unit at a controlled rate, and collecting the yarn as a unit of uniformly stretched juxtaposed windings in substantially side-byside contact and of the same diameter as the first named unit along an axis parallel to that of the first named unit at a rate greater than, and in fixed ratio with, said rate of unwinding thereby simulating a conventional slashing treatment applied to Warp yarns.

1,917,379 Lowry July 11, 1933 8 Cooper May 29, Jennings Sept. 1, Forrest Feb. 15, Burkholder Feb. 6, Sachtleben Oct. 21, Stanley et al May 8, Thornmen Nov. 24,

FOREIGN PATENTS Great Britain Nov. 6, 

